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authorStephen Boyd <swboyd@chromium.org>2019-05-14 15:45:59 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2019-05-14 19:52:52 -0700
commit442284a89a65965b044df00345c193fcc3c53ad2 (patch)
tree73973f3645aa0dda36beb8da39d82bcdacd2c733
parent449ca0c95ea261f27b7efd4ca3970a5b4e0fd30d (diff)
download96b-common-442284a89a65965b044df00345c193fcc3c53ad2.tar.gz
scripts/gdb: add a timer list command
Implement a command to print the timer list, much like how /proc/timer_list is implemented. This can be used to look at the pending timers on a crashed system. [swboyd@chromium.org: v2] Link: http://lkml.kernel.org/r/20190329220844.38234-5-swboyd@chromium.org Link: http://lkml.kernel.org/r/20190325184522.260535-5-swboyd@chromium.org Signed-off-by: Stephen Boyd <swboyd@chromium.org> Cc: Douglas Anderson <dianders@chromium.org> Cc: Nikolay Borisov <n.borisov.lkml@gmail.com> Cc: Kieran Bingham <kbingham@kernel.org> Cc: Jan Kiszka <jan.kiszka@siemens.com> Cc: Jackie Liu <liuyun01@kylinos.cn> Cc: Jason Wessel <jason.wessel@windriver.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--scripts/gdb/linux/constants.py.in13
-rw-r--r--scripts/gdb/linux/timerlist.py219
-rw-r--r--scripts/gdb/vmlinux-gdb.py1
3 files changed, 233 insertions, 0 deletions
diff --git a/scripts/gdb/linux/constants.py.in b/scripts/gdb/linux/constants.py.in
index d3319a80788a..76f46f427b96 100644
--- a/scripts/gdb/linux/constants.py.in
+++ b/scripts/gdb/linux/constants.py.in
@@ -13,8 +13,10 @@
*/
#include <linux/fs.h>
+#include <linux/hrtimer.h>
#include <linux/mount.h>
#include <linux/of_fdt.h>
+#include <linux/threads.h>
/* We need to stringify expanded macros so that they can be parsed */
@@ -44,6 +46,9 @@ LX_VALUE(SB_DIRSYNC)
LX_VALUE(SB_NOATIME)
LX_VALUE(SB_NODIRATIME)
+/* linux/htimer.h */
+LX_GDBPARSED(hrtimer_resolution)
+
/* linux/mount.h */
LX_VALUE(MNT_NOSUID)
LX_VALUE(MNT_NODEV)
@@ -52,8 +57,16 @@ LX_VALUE(MNT_NOATIME)
LX_VALUE(MNT_NODIRATIME)
LX_VALUE(MNT_RELATIME)
+/* linux/threads.h */
+LX_VALUE(NR_CPUS)
+
/* linux/of_fdt.h> */
LX_VALUE(OF_DT_HEADER)
/* Kernel Configs */
+LX_CONFIG(CONFIG_GENERIC_CLOCKEVENTS)
+LX_CONFIG(CONFIG_GENERIC_CLOCKEVENTS_BROADCAST)
+LX_CONFIG(CONFIG_HIGH_RES_TIMERS)
+LX_CONFIG(CONFIG_NR_CPUS)
LX_CONFIG(CONFIG_OF)
+LX_CONFIG(CONFIG_TICK_ONESHOT)
diff --git a/scripts/gdb/linux/timerlist.py b/scripts/gdb/linux/timerlist.py
new file mode 100644
index 000000000000..071d0dd5a634
--- /dev/null
+++ b/scripts/gdb/linux/timerlist.py
@@ -0,0 +1,219 @@
+# SPDX-License-Identifier: GPL-2.0
+#
+# Copyright 2019 Google LLC.
+
+import binascii
+import gdb
+
+from linux import constants
+from linux import cpus
+from linux import rbtree
+from linux import utils
+
+timerqueue_node_type = utils.CachedType("struct timerqueue_node").get_type()
+hrtimer_type = utils.CachedType("struct hrtimer").get_type()
+
+
+def ktime_get():
+ """Returns the current time, but not very accurately
+
+ We can't read the hardware timer itself to add any nanoseconds
+ that need to be added since we last stored the time in the
+ timekeeper. But this is probably good enough for debug purposes."""
+ tk_core = gdb.parse_and_eval("&tk_core")
+
+ return tk_core['timekeeper']['tkr_mono']['base']
+
+
+def print_timer(rb_node, idx):
+ timerqueue = utils.container_of(rb_node, timerqueue_node_type.pointer(),
+ "node")
+ timer = utils.container_of(timerqueue, hrtimer_type.pointer(), "node")
+
+ function = str(timer['function']).split(" ")[1].strip("<>")
+ softexpires = timer['_softexpires']
+ expires = timer['node']['expires']
+ now = ktime_get()
+
+ text = " #{}: <{}>, {}, ".format(idx, timer, function)
+ text += "S:{:02x}\n".format(int(timer['state']))
+ text += " # expires at {}-{} nsecs [in {} to {} nsecs]\n".format(
+ softexpires, expires, softexpires - now, expires - now)
+ return text
+
+
+def print_active_timers(base):
+ curr = base['active']['next']['node']
+ curr = curr.address.cast(rbtree.rb_node_type.get_type().pointer())
+ idx = 0
+ while curr:
+ yield print_timer(curr, idx)
+ curr = rbtree.rb_next(curr)
+ idx += 1
+
+
+def print_base(base):
+ text = " .base: {}\n".format(base.address)
+ text += " .index: {}\n".format(base['index'])
+
+ text += " .resolution: {} nsecs\n".format(constants.LX_hrtimer_resolution)
+
+ text += " .get_time: {}\n".format(base['get_time'])
+ if constants.LX_CONFIG_HIGH_RES_TIMERS:
+ text += " .offset: {} nsecs\n".format(base['offset'])
+ text += "active timers:\n"
+ text += "".join([x for x in print_active_timers(base)])
+ return text
+
+
+def print_cpu(hrtimer_bases, cpu, max_clock_bases):
+ cpu_base = cpus.per_cpu(hrtimer_bases, cpu)
+ jiffies = gdb.parse_and_eval("jiffies_64")
+ tick_sched_ptr = gdb.parse_and_eval("&tick_cpu_sched")
+ ts = cpus.per_cpu(tick_sched_ptr, cpu)
+
+ text = "cpu: {}\n".format(cpu)
+ for i in xrange(max_clock_bases):
+ text += " clock {}:\n".format(i)
+ text += print_base(cpu_base['clock_base'][i])
+
+ if constants.LX_CONFIG_HIGH_RES_TIMERS:
+ fmts = [(" .{} : {} nsecs", 'expires_next'),
+ (" .{} : {}", 'hres_active'),
+ (" .{} : {}", 'nr_events'),
+ (" .{} : {}", 'nr_retries'),
+ (" .{} : {}", 'nr_hangs'),
+ (" .{} : {}", 'max_hang_time')]
+ text += "\n".join([s.format(f, cpu_base[f]) for s, f in fmts])
+ text += "\n"
+
+ if constants.LX_CONFIG_TICK_ONESHOT:
+ fmts = [(" .{} : {}", 'nohz_mode'),
+ (" .{} : {} nsecs", 'last_tick'),
+ (" .{} : {}", 'tick_stopped'),
+ (" .{} : {}", 'idle_jiffies'),
+ (" .{} : {}", 'idle_calls'),
+ (" .{} : {}", 'idle_sleeps'),
+ (" .{} : {} nsecs", 'idle_entrytime'),
+ (" .{} : {} nsecs", 'idle_waketime'),
+ (" .{} : {} nsecs", 'idle_exittime'),
+ (" .{} : {} nsecs", 'idle_sleeptime'),
+ (" .{}: {} nsecs", 'iowait_sleeptime'),
+ (" .{} : {}", 'last_jiffies'),
+ (" .{} : {}", 'next_timer'),
+ (" .{} : {} nsecs", 'idle_expires')]
+ text += "\n".join([s.format(f, ts[f]) for s, f in fmts])
+ text += "\njiffies: {}\n".format(jiffies)
+
+ text += "\n"
+
+ return text
+
+
+def print_tickdevice(td, cpu):
+ dev = td['evtdev']
+ text = "Tick Device: mode: {}\n".format(td['mode'])
+ if cpu < 0:
+ text += "Broadcast device\n"
+ else:
+ text += "Per CPU device: {}\n".format(cpu)
+
+ text += "Clock Event Device: "
+ if dev == 0:
+ text += "<NULL>\n"
+ return text
+
+ text += "{}\n".format(dev['name'])
+ text += " max_delta_ns: {}\n".format(dev['max_delta_ns'])
+ text += " min_delta_ns: {}\n".format(dev['min_delta_ns'])
+ text += " mult: {}\n".format(dev['mult'])
+ text += " shift: {}\n".format(dev['shift'])
+ text += " mode: {}\n".format(dev['state_use_accessors'])
+ text += " next_event: {} nsecs\n".format(dev['next_event'])
+
+ text += " set_next_event: {}\n".format(dev['set_next_event'])
+
+ members = [('set_state_shutdown', " shutdown: {}\n"),
+ ('set_state_periodic', " periodic: {}\n"),
+ ('set_state_oneshot', " oneshot: {}\n"),
+ ('set_state_oneshot_stopped', " oneshot stopped: {}\n"),
+ ('tick_resume', " resume: {}\n")]
+ for member, fmt in members:
+ if dev[member]:
+ text += fmt.format(dev[member])
+
+ text += " event_handler: {}\n".format(dev['event_handler'])
+ text += " retries: {}\n".format(dev['retries'])
+
+ return text
+
+
+def pr_cpumask(mask):
+ nr_cpu_ids = 1
+ if constants.LX_NR_CPUS > 1:
+ nr_cpu_ids = gdb.parse_and_eval("nr_cpu_ids")
+
+ inf = gdb.inferiors()[0]
+ bits = mask['bits']
+ num_bytes = (nr_cpu_ids + 7) / 8
+ buf = utils.read_memoryview(inf, bits, num_bytes).tobytes()
+ buf = binascii.b2a_hex(buf)
+
+ chunks = []
+ i = num_bytes
+ while i > 0:
+ i -= 1
+ start = i * 2
+ end = start + 2
+ chunks.append(buf[start:end])
+ if i != 0 and i % 4 == 0:
+ chunks.append(',')
+
+ extra = nr_cpu_ids % 8
+ if 0 < extra <= 4:
+ chunks[0] = chunks[0][0] # Cut off the first 0
+
+ return "".join(chunks)
+
+
+class LxTimerList(gdb.Command):
+ """Print /proc/timer_list"""
+
+ def __init__(self):
+ super(LxTimerList, self).__init__("lx-timerlist", gdb.COMMAND_DATA)
+
+ def invoke(self, arg, from_tty):
+ hrtimer_bases = gdb.parse_and_eval("&hrtimer_bases")
+ max_clock_bases = gdb.parse_and_eval("HRTIMER_MAX_CLOCK_BASES")
+
+ text = "Timer List Version: gdb scripts\n"
+ text += "HRTIMER_MAX_CLOCK_BASES: {}\n".format(max_clock_bases)
+ text += "now at {} nsecs\n".format(ktime_get())
+
+ for cpu in cpus.each_online_cpu():
+ text += print_cpu(hrtimer_bases, cpu, max_clock_bases)
+
+ if constants.LX_CONFIG_GENERIC_CLOCKEVENTS:
+ if constants.LX_CONFIG_GENERIC_CLOCKEVENTS_BROADCAST:
+ bc_dev = gdb.parse_and_eval("&tick_broadcast_device")
+ text += print_tickdevice(bc_dev, -1)
+ text += "\n"
+ mask = gdb.parse_and_eval("tick_broadcast_mask")
+ mask = pr_cpumask(mask)
+ text += "tick_broadcast_mask: {}\n".format(mask)
+ if constants.LX_CONFIG_TICK_ONESHOT:
+ mask = gdb.parse_and_eval("tick_broadcast_oneshot_mask")
+ mask = pr_cpumask(mask)
+ text += "tick_broadcast_oneshot_mask: {}\n".format(mask)
+ text += "\n"
+
+ tick_cpu_devices = gdb.parse_and_eval("&tick_cpu_device")
+ for cpu in cpus.each_online_cpu():
+ tick_dev = cpus.per_cpu(tick_cpu_devices, cpu)
+ text += print_tickdevice(tick_dev, cpu)
+ text += "\n"
+
+ gdb.write(text)
+
+
+LxTimerList()
diff --git a/scripts/gdb/vmlinux-gdb.py b/scripts/gdb/vmlinux-gdb.py
index 89e4aa4f8966..033578cc4cd7 100644
--- a/scripts/gdb/vmlinux-gdb.py
+++ b/scripts/gdb/vmlinux-gdb.py
@@ -33,3 +33,4 @@ else:
import linux.rbtree
import linux.proc
import linux.constants
+ import linux.timerlist